5Van Leeuwen P, Cysarz D, Lange S, et al. Increase in regularity of fetal heart rate variability with age [ J ]. Biomed Tech ( Berl ), 2006,51 (4) :244-247.
6Park MI, Hwang JH, Cha KJ, et al. Computerized analysis of fetal heart rate parameters by gestational age [ J ]. Int J Gynaecol Obstet,2001,74(2) : 157-164.
7Lange S, Van Leeuwen P, Geue D, et al. Influence of gestational age,heart rate,gender and time of day on fetal heart rate variability [ J ]. Med Biol Eng Comput,2005,43 ( 4 ) :481-486.
8Ayoubi JM,Audibert F, Vial M,et al, Fetal heart rate and survival of the very premature newborn [ J ]. Am J Obestet Gynecol ,2002,187 : 1026-1030.
9Hill JB, Alexander JM, Sharma SK, et al, A comparison of the effects of epidural and meperidine analgesia during labor on fetal heart rate[ J]. Obstet Gynecol,2003 ,102 :333-337.
10DiPietro JA, Costigan KA, Pressman EK, et al. Antenatal origins of individual differences in heart rate [ J ]. Dev Psychobiol, 2000,37(4) :221-228.
